During years the Scientific Investigation seemed to be a space preserve to restricted spaces, laboratories, numbers and exceptional minds; its results were sober and intelligent, with charts and graphics with precise figures. But its applicability was already another thing, the numbers are not applied with easiness to the human complex matters, and they are in fact the human problems and its solution, those that demand of the social investigator. It constituted it basement for the emergency of the qualitative, numerically weak investigation but strong to cope with the complexity of the real world research”. Without being exclusivity of the Qualitative Investigation, one of their most important traditions reside in the Case Studies a procedure that deserve their domain on the part of the social investigators and in particular the psychologists.